Apparatuses and methods for cutting a reverse spot-face in a workpiece

ABSTRACT

A reverse spot-facing tool for cutting a reverse spot-face in a workpiece using a reverse spot-facing cutter configured to engage a pilot shaft having a first end and a second end is disclosed. The workpiece comprises a through hole having a central axis. The reverse spot-facing tool comprises a stop configured to be located between the first end and the second end of the pilot shaft; a biasing assembly that generates a first thrust force and an equal and opposite second thrust force when the reverse spot-facing cutter is cutting the reverse spot face; and a thrust bearing configured to be positioned between the biasing assembly and the stop. When the reverse spot-facing cutter is cutting the reverse spot-face, the thrust bearing transmits the second thrust force from the biasing assembly to the stop, and the biasing assembly transmits the first thrust force to the workpiece.

BACKGROUND

This application is a continuation of and claims the benefit of U.S.patent application Ser. No. 15/275,735, filed Sep. 26, 2016, which is acontinuation of U.S. patent application Ser. No. 14/481,484 (now U.S.Pat. No. 9,486,861), filed Sep. 9, 2014, the disclosure of which isexpressly incorporated herein by reference in its entirety.

Cutting a reverse spot-face in a workpiece with conventional spot-facingequipment is time consuming, difficult to perform properly, and tiringfor the operator. More specifically, it may be difficult to maintain thereverse spot-facing cutter in coaxial alignment with a hole that is tobe provided with the reverse spot-face. Furthermore, while cutting thereverse spot-face, pulling force must be continuously exerted by theoperator on the pilot shaft of the reverse spot-facing cutter tomaintain cutting action. Additionally, the operator must periodicallyinterrupt the cutting process to prevent excessive penetration of theworkpiece by the reverse spot-facing cutter.

SUMMARY

Accordingly, apparatuses and methods, intended to address theabove-identified concerns, would find utility.

The following is a non-exhaustive list of examples, which may or may notbe claimed, of the subject matter according the present disclosure.

One example of the present disclosure relates to a reverse spot-facingtool for cutting a reverse spot-face in a workpiece using a reversespot-facing cutter configured to engage a pilot shaft having a first endand a second end. The workpiece comprises a through hole having acentral axis. The reverse spot-facing tool comprises a stop configuredto be located between the first end and the second end of the pilotshaft; a biasing assembly that generates a first thrust force and asecond thrust force equal and opposite to the first thrust force whenthe reverse spot-facing cutter is cutting the reverse spot face; and athrust bearing configured to be positioned between the biasing assemblyand the stop. When the reverse spot-facing cutter is cutting the reversespot-face, the thrust bearing transmits the second thrust force from thebiasing assembly to the stop, and the biasing assembly transmits thefirst thrust force to the workpiece.

Another example of the present disclosure relates to a reversespot-facing tool for cutting a reverse spot-face in a workpiece. Theworkpiece comprises a through hole having a central axis. The reversespot-facing tool comprises a pilot shaft and a reverse spot-facingcutter configured to be coupled to the pilot shaft. The reversespot-facing tool also comprises a stop, in turn comprising a firstthrough opening configured to receive the pilot shaft and a lockconfigured to fix the stop along the pilot shaft. Thereverse-spot-facing tool further comprises a thrust bearing and abiasing assembly. The biasing assembly generates a first thrust forceand a second thrust force equal and opposite to the first thrust forcewhen the reverse spot-facing cutter is cutting the reverse spot-face.The biasing assembly comprises a workpiece-engaging member comprising athird end configured to face the workpiece, a fourth end opposite thethird end and configured to face the stop, and a second through openingextending between the third end and the fourth end. The second throughopening is bounded by a first wall. The workpiece-engaging member alsocomprises a first abutment surface configured to engage the workpiece.The biasing assembly also comprises a stop-engaging member, in turncomprising a fifth end configured to face the workpiece, a sixth endopposite the fifth end and configured to face the stop, and a thirdthrough opening extending between the fifth end and the sixth end. Thethird through opening is bounded by a second wall. The stop-engagingmember further comprises a second abutment surface configured to engagethe thrust bearing. The thrust bearing is configured to be positionedbetween the biasing assembly and the stop. The workpiece-engaging memberand the stop-engaging member are configured to be adjustablyinterconnected. When the reverse spot-facing cutter is cutting thereverse spot-face, the thrust bearing transmits the second thrust forcefrom the biasing assembly to the stop, and the biasing assemblytransmits the first thrust force to the workpiece.

Yet another example of the present disclosure relates to a method ofcutting a reverse spot-face having a depth in a workpiece. The workpiececomprises an obverse side, a reverse side, and a through hole with thecentral axis. The method comprises installing a pilot shaft in thethrough hole such that a stop is along the pilot shaft on the obverseside of the workpiece, a biasing assembly is along the pilot shaftbetween the workpiece and the stop, and a thrust bearing is between thebiasing assembly and the stop. The method further comprises attaching areverse spot-facing cutter to the pilot shaft on the reverse side of theworkpiece; biasing the reverse spot-facing cutter against the reverseside of the workpiece with a preload by generating a first thrust forceagainst the obverse side of the workpiece and a second thrust forceopposite the first thrust force against the stop by adjusting thebiasing assembly; and rotating the reverse spot-facing cutter via thepilot shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described examples of the present disclosure in generalterms, reference will now be made to the accompanying drawings, whichare not necessarily drawn to scale, and wherein like referencecharacters designate the same or similar parts throughout the severalviews, and wherein:

FIG. 1A is a first portion of a block diagram of a reverse spot-facingtool, according to one or more examples of the present disclosure;

FIG. 1B is a second portion of the block diagram of the reversespot-facing tool, according to one or more examples of the presentdisclosure;

FIG. 2 is a schematic, side elevational, environmental view of thereverse spot-facing tool of FIGS. 1A and 1B, according to one or moreexamples of the present disclosure;

FIG. 3A is a schematic sectional view of a workpiece-engaging member ofthe reverse spot-facing tool of FIGS. 1A and 1B, according to one ormore examples of the present disclosure;

FIG. 3B is a schematic sectional view of a workpiece-engaging member ofthe reverse spot-facing tool of FIGS. 1A and 1B, according to one ormore examples of the present disclosure;

FIG. 4A is a schematic perspective exploded view of a biasing assemblyof the reverse spot-facing tool of FIGS. 1A and 1B, according to one ormore examples of the present disclosure;

FIG. 4B is a schematic perspective exploded view of a biasing assemblyof the reverse spot-facing tool of FIGS. 1A and 1B, according to one ormore examples of the present disclosure;

FIG. 4C is a schematic perspective exploded view of a biasing assemblyof the reverse spot-facing tool of FIGS. 1A and 1B, according to one ormore examples of the present disclosure;

FIG. 4D is a schematic perspective exploded view of a biasing assemblyof the reverse spot-facing tool of FIGS. 1A and 1B, according to one ormore examples of the present disclosure;

FIG. 5 is a schematic side elevational view of a workpiece-engagingmember of the reverse spot-facing tool of FIGS. 1A and 1B, according toone or more examples of the present disclosure;

FIG. 6 is a schematic exploded, perspective view of the reversespot-facing tool of FIGS. 1A and 1B, according to one or more examplesof the present disclosure;

FIG. 7 is a schematic, sectional view of a biasing assembly of thereverse spot-facing tool of FIGS. 1A and 1B, according to one or moreexamples of the present disclosure;

FIG. 8 is a schematic perspective view of a reverse spot-facing cutterand pilot shaft of the reverse spot-facing tool of FIGS. 1A and 1B,according to one or more examples of the present disclosure;

FIG. 9 is a schematic perspective view of a pilot shaft of the reversespot-facing tool of FIGS. 1A and 1B, according to one or more examplesof the present disclosure;

FIG. 10 is a block diagram of a method of cutting a reverse spot-face,according to one or more examples of the present disclosure;

FIG. 11 is a block diagram of aircraft production and servicemethodology; and

FIG. 12 is a schematic illustration of an aircraft.

DETAILED DESCRIPTION

In FIGS. 1A and 1B, referred to above, solid lines, if any, connectingvarious elements and/or components may represent mechanical, electrical,fluid, optical, electromagnetic and other couplings and/or combinationsthereof. As used herein, “coupled” means associated directly as well asindirectly. For example, a member A may be directly associated with amember B, or may be indirectly associated therewith, e.g., via anothermember C. It will be understood that not all relationships between thevarious disclosed elements are necessarily represented. Accordingly,couplings other than those depicted in the block diagrams may alsoexist. Dashed lines, if any, connecting the various elements and/orcomponents represent couplings similar in function and purpose to thoserepresented by solid lines; however, couplings represented by the dashedlines may either be selectively provided or may relate to alternative oroptional examples of the present disclosure Likewise, elements and/orcomponents, if any, represented with dashed lines, indicate alternativeor optional examples of the present disclosure. Environmental elements,if any, are represented with dotted lines. Virtual (imaginary) elementsmay also be shown for clarity. Those skilled in the art will appreciatethat some of the features illustrated in FIGS. 1A and 1B may be combinedin various ways without the need to include other features described inFIGS. 1A and 1B, other drawing figures, and/or the accompanyingdisclosure, even though such combination or combinations are notexplicitly illustrated herein. Similarly, additional features notlimited to the examples presented, may be combined with some or all ofthe features shown and described herein.

In FIGS. 1A, 1B, and 11, referred to above, the blocks may representoperations and/or portions thereof and lines connecting the variousblocks do not imply any particular order or dependency of the operationsor portions thereof. FIGS. 1A, 1B, and 11 and the accompanyingdisclosure describing the operations of the method(s) set forth hereinshould not be interpreted as necessarily determining a sequence in whichthe operations are to be performed. Rather, although one illustrativeorder is indicated, it is to be understood that the sequence of theoperations may be modified when appropriate. Accordingly, certainoperations may be performed in a different order or simultaneously.Additionally, those skilled in the art will appreciate that not alloperations described need be performed.

In the following description, numerous specific details are set forth toprovide a thorough understanding of the disclosed concepts, which may bepracticed without some or all of these particulars. In other instances,details of known devices and/or processes have been omitted to avoidunnecessarily obscuring the disclosure. While some concepts will bedescribed in conjunction with specific examples, it will be understoodthat these examples are not intended to be limiting.

Unless otherwise indicated, the terms “first,” “second,” etc. are usedherein merely as labels, and are not intended to impose ordinal,positional, or hierarchical requirements on the items to which theseterms refer. Moreover, reference to, e.g., a “second” item does notrequire or preclude the existence of, e.g., a “first” or lower-numbereditem, and/or, e.g., a “third” or higher-numbered item.

Reference herein to “one example” means that one or more feature,structure, or characteristic described in connection with the example isincluded in at least one implementation. The phrase “one example” invarious places in the specification may or may not be referring to thesame example.

Illustrative, non-exhaustive examples, which may or may not be claimed,of the subject matter according the present disclosure are providedbelow.

Referring e.g., to FIGS. 1A, 1B, 2, and 6, the instant paragraphpertains to example 1 of the present disclosure. Example 1 relates toreverse spot-facing tool 100 for cutting reverse spot-face R inworkpiece W using reverse spot-facing cutter 102 configured to engagepilot shaft 104 having first end 101 and second end 105. In example 1,workpiece W comprises a through hole H having central axis A. Reversespot-facing tool 100 comprises stop 132 configured to be located betweenfirst end 101 and second end 105 of pilot shaft 104; biasing assembly109 that generates first thrust force F1 and second thrust force F2equal and opposite to first thrust force F1 when reverse spot-facingcutter 102 is cutting reverse spot face R; and thrust bearing 126configured to be positioned between biasing assembly 109 and stop 132.When reverse spot-facing cutter 102 is cutting reverse spot-face R,thrust bearing 126 transmits second thrust force F2 from biasingassembly 109 to stop 132, and biasing assembly 109 transmits firstthrust force F1 to workpiece W.

Central axis A of hole H is coincident with the drilling axis fromforming hole H. The purpose of stop 132 is to provide a vehicle fortransmitting second thrust force F2 to pilot shaft 104.

Transmission of forces F1 and F2 respectively to workpiece W and pilotshaft 104 eliminates the need for having the worker constantly pull ondrill D to cause reverse spot-facing cutter 102 to bear againstworkpiece W during cutting. Worker fatigue and demands on workerattention are thus decreased.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS. 2,4A-4D, 6, and 7, the instant paragraph pertains to example 2 of thepresent disclosure. In example 2, which includes the subject matter ofexample 1, biasing assembly 109 comprises workpiece-engaging member 110,in turn comprising third end 161 configured to face workpiece W, fourthend 163 opposite third end 161 and configured to face stop 132, andsecond through opening 112 extending between third end 161 and fourthend 163. Second through opening 112 has first wall 127. Theworkpiece-engaging member 110 further comprises first abutment surface116 configured to engage workpiece W. Biasing assembly 109 alsocomprises stop-engaging member 118, in turn comprising fifth end 165configured to face workpiece W, sixth end 167 opposite fifth end 165 andconfigured to face stop 132, and third through opening 122 extendingbetween fifth end 165 and sixth end 167. Third through opening 122 hassecond wall 129. The stop-engaging member 118 further comprises secondabutment surface 169 configured to engage thrust bearing 126.Workpiece-engaging member 110 and stop-engaging member 118 areconfigured to be adjustably interconnected.

Adjustable interconnection of workpiece-engaging member 110 andstop-engaging member 118 enables first and second thrust forces F1, F2to be generated.

Reference to components of reverse spot-facing tool 100 as beingconfigured to face workpiece W or stop 132 is predicated on reversespot-facing tool 100 being in an operable condition, installed onworkpiece W (e.g., as in FIG. 2). Reference to components of reversespot-facing tool 100 as being configured to engage another componentrefers to the order in which these components are assembled when thereverse spot-facing tool 100 is installed on workpiece W, andencompasses abutment of components and/or environmental elements withreverse spot-facing tool 100 in an assembled condition.

Biasing assembly 109 fits over pilot shaft 104 and between workpiece Wand stop 104, thereby being able to transmit first and second thrustforces F1, F2 to workpiece W and stop 132, and thereby creating preload144 (see FIGS. 1B and 2), as will be described hereinafter.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 2,the instant paragraph pertains to example 3 of the present disclosure.In example 3, which includes the subject matter of example 2, whenreverse spot-facing cutter 102 is cutting reverse spot face R, thrustbearing 126 transmits second thrust force F2 from second abutmentsurface 169 of stop-engaging member 118 to stop 132. First abutmentsurface 116 of workpiece-engaging member 110 transmits first thrustforce F1 to workpiece W.

Thrust bearing 126 transmits second thrust force F2 to stop 132 so that,with pilot shaft 104 pulling on reverse spot-face cutter 102, preload144 is created. Simultaneously, rotation of pilot shaft 104 relative tobiasing assembly 109 when cutting reverse spot-face 102 and whenadjusting biasing assembly 109 is accommodated by thrust bearing 126,thereby also minimizing wear of stop 132 and biasing assembly 109.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 7,the instant paragraph pertains to example 4 of the present disclosure.In example 4, which includes the subject matter of any of examples 2 and3, at least a portion of first wall 127 of second through opening 112 ofworkpiece-engaging member 110 is smooth. At least a portion of secondwall 129 of third through opening 122 of stop-engaging member 118 issmooth.

Smooth portions of first and second walls 127, 129, enable a close,sliding fit of pilot shaft 104 with biasing assembly 109, therebyproviding the required alignment of pilot shaft 104 for cutting reversespot-face R.

Still referring generally to FIGS. 1A and 1B and particularly to e.g.FIG. 7, the instant paragraph pertains to example 5 of the presentdisclosure. In example 5, which includes the subject matter of any ofexamples 2 and 3, second through opening 112 of workpiece-engagingmember 110 comprises linear bearing 176.

The service lives of workpiece-engaging member 110 and pilot shaft 104,which rotates relative to the workpiece-engaging member 110 duringcutting of reverse spot-face R, may be extended by using linear bearing176.

Continuing to refer generally to FIGS. 1A and 1B, and particularly toe.g. FIG. 7, the instant paragraph pertains to example 6 of the presentdisclosure. In example 6, which includes the subject matter of any ofexamples 2, 3, and 5, third through opening 122 of stop-engaging member118 comprises linear bearing 178.

The service lives of stop-engaging member 118 and pilot shaft 104, whichrotates relative to the stop-engaging member 118 during cutting ofreverse spot-face R, may be extended by using linear bearing 178.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS. 2,3A-3B, 4A-4D, and 7, the instant paragraph pertains to example 7 of thepresent disclosure. In example 7, which includes the subject matter ofany of examples 2-6, pilot shaft 104 has a sliding fit with secondthrough opening 112 of workpiece-engaging member 110.

A close, sliding fit of pilot shaft 104 within second through opening112 of workpiece-engaging member 110 promotes proper alignment ofreverse spot-facing cutter 102 relative to workpiece W.

Continuing to refer generally to FIGS. 1A and 1B and particularly toe.g. FIGS. 2, 3A-3B, 4A-4D, and 7, the instant paragraph pertains toexample 8 of the present disclosure. In example 8, which includes thesubject matter of any of examples 2-7, pilot shaft 104 has a sliding fitwith third through opening 122 of stop-engaging member 118.

A close, sliding fit of pilot shaft 104 within third through opening 122of stop-engaging member 118 promotes proper alignment of reversespot-facing cutter 102 to workpiece W.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS. 2,4A-4D, 6, and 7, the instant paragraph pertains to example 9 of thepresent disclosure. In example 9, which includes the subject matter ofany of examples 2-8, biasing assembly 109 comprises threaded coupling120 between workpiece-engaging member 110 and stop-engaging member 118.Threaded coupling 120 is infinitely adjustable along its length.

The length of threaded coupling 120 refers to an extent along whichthreads 120A of workpiece-engaging member 110 mesh with threads 120B ofstop-engaging member 118. This length is variable, depending upon theextent to which stop-engaging member 118 has been threaded intowork-piece engaging member 110. The length of threaded coupling 120defines a range of adjustment provided by biasing assembly 109. Infiniteadjustability of threaded coupling 120 along the available range ofadjustment enables precise control of the magnitude of preload onreverse spot-facing cutter 102.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS. 2,4A-4D, 6, and 7, the instant paragraph pertains to example 10 of thepresent disclosure. In example 10, which includes the subject matter ofany of examples 2-9, workpiece-engaging member 110 further comprisesfirst rotational engagement feature 139.

First rotational engagement feature 139 promotes positive manual graspof workpiece-engaging member 110 when rotating workpiece-engaging member110 relative to stop-engaging member 118 to generate first and secondthrust forces F1, F2, corresponding to desired preload 144. Manualgrasping of workpiece-engaging member 110 is a convenient alternative tousing a tool, such as a wrench (not shown).

Those skilled in the art will appreciate that first rotationalengagement feature 139 broadly encompasses a number of specific forms,several of which are described hereinafter. The same holds true forsecond rotational engagement feature 141, and for first and secondinterlock features 138, 143, all to be described below.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 4A,the instant paragraph pertains to example 11 of the present disclosure.In example 11, which includes the subject matter of example 10, firstrotational engagement feature 139 comprises first friction surface 139B.

First friction surface 139B enables slip-resistant manual grasp ofstop-engaging member 118. First friction surface 139B may compriseknurling, ridging, application of a light tack adhesive, application ofa high friction rubber or other coating, and other treatments.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS. 2and 4C-4D, the instant paragraph pertains to example 12 of the presentdisclosure. In example 12, which includes the subject matter of example10, first rotational engagement feature 139 comprises first handle 139Aprojecting from workpiece-engaging member 110.

First handle 139A enables positive manual grasp of workpiece-engagingmember 110 when adjusting preload 144 and increases leverage availableto rotate workpiece-engaging member 110 compared to the use of firstfriction surface 139B, for example.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS.3A-3B, 4B-4D, 6, and 7, the instant paragraph pertains to example 13 ofthe present disclosure. In example 13, which includes the subject matterof example 10, first rotational engagement feature 139 comprises firstinterlock feature 138.

First interlock feature 138 accommodates engagement ofworkpiece-engaging member 110 by an implement such as a tool or handle,rather than by direct manual grasp, to rotate stop-engaging member 118relative to workpiece-engaging member 110 when adjusting first andsecond thrust forces F1, F2, and hence preload 144.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS.3A-3B, 4B, 5, and 6, the instant paragraph pertains to example 14 of thepresent disclosure. In example 14, which includes the subject matter ofexample 13, first interlock feature 138 comprises first opposed,substantially parallel wrench surfaces 138A.

As used herein, “substantially parallel” means parallel withinmanufacturing tolerances, or alternatively, usable with wrenches havingnominally parallel opposing jaw surfaces. First opposed, substantiallyparallel wrench surfaces 138A enable grasp of workpiece-engaging member110 by a wrench when adjusting first and second thrust forces F1, F2,and hence preload 144.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS. 2,4C-4D, and 7, the instant paragraph pertains to example 15 of thepresent disclosure. In example 15, which includes the subject matter ofexample 13, first interlock feature 138 comprises first engagementrecess 138B.

First engagement recess 138B is any recess other than first opposed,substantially parallel wrench surfaces 138A in workpiece-engaging member110. First engagement recess 138B receives an implement, such as a rodor a handle, enabling an operator to hold workpiece-engaging member 110in place, or alternatively, to rotate workpiece-engaging member 110relative to stop-engaging member 118 when adjusting the preload. Firstengagement recess 138B may be a threaded hole, for example, to receivefirst handle 139A, or in another example, may be a groove to receive atool resembling a tuning fork (this option is not shown), among otherpossibilities.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS. 2,4A, 4C, 4D, 6 and 7, the instant paragraph pertains to example 16 of thepresent disclosure. In example 16, which includes the subject matter ofany of examples 2-15, stop-engaging member 118 further comprises secondrotational engagement feature 141.

Second rotational engagement feature 141 facilitates manual grasp ofstop-engaging member 118 to accomplish mutual rotation ofworkpiece-engaging member 110 and stop-engaging member 118 forgenerating first and second thrust forces F1, F2, thereby settingpreload 144 to an appropriate value.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS.4A, 4C, and 7, the instant paragraph pertains to example 17 of thepresent disclosure. In example 17, which includes the subject matter ofexample 16, second rotational engagement feature 141 comprises secondfriction surface 141B on stop-engaging member 118.

Second friction surface 141B enables slip-resistant manual grasp ofstop-engaging member 118 when adjusting biasing assembly 109 to generatefirst and second thrust forces F1, F2, thus setting preload 144. Secondfriction surface 141B may comprise knurling, ridging, application of alight tack adhesive, application of a high friction rubber or othercoating, and other treatments.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 2,the instant paragraph pertains to example 18 of the present disclosure.In example 18, which includes the subject matter of example 16, secondrotational engagement feature 141 comprises second handle 141Aprojecting from stop-engaging member 118.

Second handle 141A enables positive manual grasp of stop-engaging member118 when adjusting biasing assembly 109 to generate first and secondthrust forces F1, F2, and thereby setting preload 144 to an appropriatevalue.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS.4B, 4D, and 6, the instant paragraph pertains to example 19 of thepresent disclosure. In example 19, which includes the subject matter ofexample 16, second rotational engagement feature 141 comprises secondinterlock feature 143.

Second interlock feature 143 accommodates rotation of stop-engagingmember 118 relative to workpiece-engaging member 110 by an implementsuch as a tool or a handle, rather than via direct manual grasp.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIGS. 4Band 4D, the instant paragraph pertains to example 20 of the presentdisclosure. In example 20, which includes the subject matter of example19, second interlock feature 143 comprises second opposed, substantiallyparallel wrench surfaces 143B.

Second opposed, substantially parallel wrench surfaces 143B enable graspof stop-engaging member 118 by a wrench when adjusting biasing assembly109 to set preload 144.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 2,the instant paragraph pertains to example 21 of the present disclosure.In example 21, which includes the subject matter of example 19, secondinterlock feature 143 comprises second engagement recess 143A.

Second engagement recess 143A is any recess other than second opposed,substantially parallel wrench surfaces 143B in stop-engaging member 118,which receives or engages an implement, such as a rod or handle,enabling a worker to hold stop-engaging member 118 in place, oralternatively, to rotate stop-engaging member 118 relative toworkpiece-engaging member 110 when adjusting preload 144. Secondengagement recess 143A may be a threaded hole (not shown), for example,to receive second handle 141A where the latter has a threaded attachmentshank, or for example, may be a groove to receive a tool resembling atuning fork (this option is not shown), among other possibilities (noneshown).

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 2,the instant paragraph pertains to example 22 of the present disclosure.In example 22, which includes the subject matter of any of examples1-21, reverse spot-facing cutter 102 and biasing assembly 109 are onopposite sides of workpiece W when reverse spot-facing cutter 102 iscutting reverse spot face R.

Accordingly, opposing first and second thrust forces F1, F2, capable ofbeing generated by biasing assembly 109 along central axis A, createpreload 144 without requiring the operator to exert a pulling force onsecond end 105 of pilot shaft 104.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 5,the instant paragraph pertains to example 23 of the present disclosure.In example 23, which includes the subject matter of any of examples2-21, workpiece-engaging member 110 has first maximum transversedimension 156 at first abutment surface 116, and second maximumtransverse dimension 158 away from first abutment surface 116. Secondmaximum transverse dimension 158 is greater in magnitude than firstmaximum transverse dimension 156.

Accordingly, depending on the geometry of the workpiece W, access toworkpiece W may be improved.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 5,the instant paragraph pertains to example 24 of the present disclosure.In example 24, which includes the subject matter of any of examples2-23, workpiece-engaging member 110 further comprises guide surface 160configured to center pilot shaft 104 relative to through hole H inworkpiece W when reverse spot-facing tool 100 is installed on workpieceW.

Guide surface 160 occupies hole H with close fit thereto. Centeringpilot shaft 104 relative to hole H using workpiece-engaging member 110eliminates the need for separately centering reverse spot-facing cutter102 relative to workpiece W.

Still referring generally to FIGS. 1A and 1B and particularly to e.g.FIG. 5, the instant paragraph pertains to example 25 of the presentdisclosure. In example 25, which includes the subject matter of example24, workpiece-engaging member 110 further comprises tapered externalsurface 164 adjacent guide surface 160.

Accordingly, depending on the geometry of the workpiece W, access toworkpiece W may be improved.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 2,the instant paragraph pertains to example 26 of the present disclosure.In example 26, which includes the subject matter of any of examples 24and 25, guide surface 160 is configured to align pilot shaft 104 withcentral axis A of through hole H.

Aligning pilot shaft 104 with central axis A promotes making reversespot-face R perpendicular to central axis A of hole H. Aligning pilotshaft 104 with central axis A using workpiece-engaging member 110eliminates the need for a separately aligning and/or centering reversespot-facing cutter 102 relative to workpiece W.

Still referring generally to FIGS. 1A and 1B and particularly to e.g.FIG. 2, the instant paragraph pertains to example 27 of the presentdisclosure. In example 27, which includes the subject matter of any ofexamples 24-26, guide surface 160 is configured to have a sliding fitwith through hole H.

Sliding fit enables mutual alignment of biasing assembly 109 withworkpiece W.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 9,the instant paragraph pertains to example 28 of the present disclosure.In example 28, which includes the subject matter of any of examples1-27, stop 132 is monolithic with pilot shaft 104.

Making stop 132 monolithic with pilot shaft 104 eliminates an assemblystep (that of locking separate stop 132 to pilot shaft 104) wheninstalling reverse spot-facing tool 100 on workpiece W.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 6,the instant paragraph pertains to example 29 of the present disclosure.In example 29, which includes the subject matter of any of examples1-27, stop 132 comprises first through opening 152, configured toreceive pilot shaft 104, and lock 154, configured to fix stop 132 alongpilot shaft 104.

Lock 154 may comprise setscrew 155, for example. Setscrew 155 may bedriven by allen wrench T. In example 29, stop 132 is separate from pilotshaft 104, which enables reverse spot-facing tool 100 to utilize apre-existing or conventional pilot shaft 104 and reverse spot-facingcutter 102.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 9,the instant paragraph pertains to example 30 of the present disclosure.In example 30, which includes the subject matter of example 29, firstthrough opening 152 of stop 132 is configured to have a sliding fit withpilot shaft 104.

This arrangement e.g. stabilizes stop 132 against potential wobble onpilot shaft 104 when installed thereon, which in turn increases securityof setscrew 155.

Referring e.g., to FIGS. 1A, 1B, 2, and 6, the instant paragraphpertains to example 31 of the present disclosure. Example 31 relates toreverse spot-facing tool 100 for cutting reverse spot-face R inworkpiece W. In example 31, workpiece W comprises through hole H havingcentral axis A. Reverse spot-facing tool 100 comprises pilot shaft 104;reverse spot-facing cutter 132 configured to be coupled to pilot shaft104; and stop 132. Stop 132 comprises first through opening 152,configured to receive pilot shaft 104, and lock 154, configured to fixstop 132 along pilot shaft 104. Reverse spot-facing tool 100 alsocomprises thrust bearing 126 and biasing assembly 109 that generatesfirst thrust force F1 and second thrust force F2 equal and opposite tofirst thrust force F1 when reverse spot-facing cutter 102 is cuttingreverse spot-face R. Biasing assembly 109 comprises workpiece-engagingmember 110, in turn comprising third end 161 configured to faceworkpiece W, fourth end 163 opposite end 161 and configured to face stop132, and second through opening 112 extending between third end 161 andfourth end 163. Second through opening 112 is bounded by first wall 127.Workpiece-engaging member 110 also comprises first abutment surface 116configured to engage workpiece W. Biasing assembly 109 also comprisesstop-engaging member 118, in turn comprising fifth end 165 configured toface workpiece W, sixth end 167 opposite fifth end 165 and configured toface stop 132, and third through opening 122 extending between fifth end165 and sixth end 167. Third through opening 122 is bounded by secondwall 129. Stop-engaging member 118 further comprises second abutmentsurface 169 configured to engage thrust bearing 126. Thrust bearing 126is configured to be positioned between biasing assembly 109 and stop132. Workpiece-engaging member 110 and stop-engaging member 118 areconfigured to be adjustably interconnected. When reverse spot-facingcutter 102 is cutting reverse spot-face R, thrust bearing 126 transmitssecond thrust force F2 from biasing assembly 109 to stop 132 and biasingassembly 109 transmits first thrust force F1 to workpiece W.

Transmission of forces F1 and F2 respectively to workpiece W and pilotshaft 104 eliminates the need for having the worker constantly pull ondrill D to cause reverse spot-facing cutter 102 to bear againstworkpiece W during cutting. Worker fatigue and demands on workerattention are thus decreased.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 6,the instant paragraph pertains to example 32 of the present disclosure.In example 32, which includes the subject matter of example 31, reversespot-facing cutter 102 and pilot shaft 104 include a mechanicalinterlock 107 configured to demountably couple reverse spot-facingcutter 102 to pilot shaft 104.

Mechanical interlock 107, schematically depicted herein as a bayonetconnection, may include interfit characteristics of bayonet connections,but may take forms other than that depicted. Mechanical interlock 107assures retention of reverse spot-facing cutter 102 to pilot shaft 104when cutting reverse spot-face R.

Referring generally to FIGS. 1A and 1B and particularly to e.g. FIG. 8,the instant paragraph pertains to example 33 of the present disclosure.In example 33, which includes the subject matter of example 31, reversespot-facing cutter 102 and pilot shaft 104 are monolithicallyinterconnected.

Making stop 132 monolithic with pilot shaft 104 eliminates an assemblystep (that of locking separate stop 132 to pilot shaft 104) wheninstalling reverse spot-facing tool 100 on workpiece W.

Referring e.g., to FIGS. 1A, 1B, 2, 6, and 10, the instant paragraphpertains to example 34 of the present disclosure. Example 34 relates tomethod 200 of cutting reverse spot-face R in workpiece W. Workpiece Wcomprises obverse side 140, reverse side 142, and through hole H withcentral axis A. In example 34, method 200 comprises installing pilotshaft 104 in through hole H, such that stop 132 is along pilot shaft 104on obverse side 140 of workpiece W, biasing assembly 109 is along pilotshaft 104 between workpiece W and stop 132, and thrust bearing 126 isbetween biasing assembly 109 and stop 132 (block 202). Method 200further comprises attaching reverse spot-facing cutter 102 to pilotshaft 104 on reverse side 142 of workpiece W (block 204); biasingreverse spot-facing cutter 102 against reverse side 142 of workpiece Wwith preload 144 by generating first thrust force F1 against obverseside 140 of workpiece W and second thrust force F2 opposite first thrustforce F1 against stop 132 by adjusting biasing assembly 109 (block 206);and rotating reverse spot-facing cutter 102 via pilot shaft 104 (block208).

Reverse spot-face R is thereby created without obliging a worker toconstantly pull on drill D to cause reverse spot-facing cutter 102 tobear against workpiece W during cutting. Worker fatigue and demands onworker attention are thus decreased.

Continuing to refer generally to FIGS. 1A, 1B, 2, and 6, andparticularly to e.g. FIG. 10, the instant paragraph pertains to example35 of the present disclosure. In example 35, which includes the subjectmatter of example 34, method 200 further comprises aligning reversespot-facing cutter 102 with central axis A of through hole H usingbiasing assembly 109 (block 210).

Using biasing assembly 109 for alignment eliminates the need for aseparate centering step, thereby simplifying reverse spot-facingoperation.

Continuing to refer generally to FIGS. 1A, 1B, 2, and 6, andparticularly to e.g. FIG. 10, the instant paragraph pertains to example36 of the present disclosure. In example 36, which includes the subjectmatter of any of examples 34 and 35, method 200 further comprisesprogressively reducing preload 144 responsive to advancing reversespot-facing cutter 102 into workpiece W while rotating reversespot-facing cutter 102 (block 212).

Reducing preload 144 responsive to advancing reverse spot-facing cutter102 into the workpiece automatically terminates cutting of reversespot-face R.

Continuing to refer generally to FIGS. 1A, 1B, 2, and 6, andparticularly to e.g. FIG. 10, the instant paragraph pertains to example37 of the present disclosure. In example 37, which includes the subjectmatter of example 36, method 200 further comprises terminating preload144 when first thrust force F1 and second thrust force F2 fullydissipate (block 214).

Terminating preload 144 when first and second thrust forces F1 and F2fully dissipate provides automatic control of the cutting depth.

Continuing to refer generally to FIGS. 1A, 1B, 2, and 6, andparticularly to e.g. FIG. 10, the instant paragraph pertains to example38 of the present disclosure. In example 38, which includes the subjectmatter of any of examples 34-37, rotating reverse spot-facing cutter 102via pilot shaft 104 comprises rotating pilot shaft 104 with rotary driveD (block 216).

Rotary drive D may be an electric hand drill, or alternatively, may be adrive utilizing pneumatic or hydraulic pressure, spring force, manualforce, and other sources of power. Using a rotary drive, such asdescribed above, enables selection of a particular cutting speedrequired for a given operation.

Examples of the present disclosure may be described in the context ofaircraft manufacturing and service method 1100 as shown in FIG. 11 andaircraft 1102 as shown in FIG. 12. During pre-production, illustrativemethod 1100 may include specification and design (block 1104) ofaircraft 1102 and material procurement (block 1106). During production,component and subassembly manufacturing (block 1108) and systemintegration (block 1110) of aircraft 1102 may take place. Thereafter,aircraft 1102 may go through certification and delivery (block 1112) tobe placed in service (block 1114). While in service, aircraft 1102 maybe scheduled for routine maintenance and service (block 1116). Routinemaintenance and service may include modification, reconfiguration,refurbishment, etc. of one or more systems of aircraft 1102.

Each of the processes of illustrative method 1100 may be performed orcarried out by a system integrator, a third party, and/or an operator(e.g., a customer). For the purposes of this description, a systemintegrator may include, without limitation, any number of aircraftmanufacturers and major-system subcontractors; a third party mayinclude, without limitation, any number of vendors, subcontractors, andsuppliers; and an operator may be an airline, leasing company, militaryentity, service organization, and so on.

As shown in FIG. 12, aircraft 1102 produced by illustrative method 1100may include airframe 1118 with a plurality of high-level systems 1120and interior 1122. Examples of high-level systems 1120 include one ormore of propulsion system 1124, electrical system 1126, hydraulic system1128, and environmental system 1130. Any number of other systems may beincluded. Although an aerospace example is shown, the principlesdisclosed herein may be applied to other industries, such as theautomotive industry. Accordingly, in addition to aircraft 1102, theprinciples disclosed herein may apply to other vehicles, e.g., landvehicles, marine vehicles, space vehicles, etc.

Apparatus(es) and method(s) shown or described herein may be employedduring any one or more of the stages of the manufacturing and servicemethod 1100. For example, components or subassemblies corresponding tocomponent and subassembly manufacturing 1108 may be fabricated ormanufactured in a manner similar to components or subassemblies producedwhile aircraft 1102 is in service. Also, one or more examples of theapparatus(es), method(s), or combination thereof may be utilized duringproduction stages 1108 and 1110, for example, by substantiallyexpediting assembly of or reducing the cost of aircraft 1102. Similarly,one or more examples of the apparatus or method realizations, or acombination thereof, may be utilized, for example and withoutlimitation, while aircraft 1102 is in service, e.g., maintenance andservice stage (block 1116).

Different examples of the apparatus(es) and method(s) disclosed hereininclude a variety of components, features, and functionalities. Itshould be understood that the various examples of the apparatus(es) andmethod(s) disclosed herein may include any of the components, features,and functionalities of any of the other examples of the apparatus(es)and method(s) disclosed herein in any combination, and all of suchpossibilities are intended to be within the spirit and scope of thepresent disclosure.

Many modifications of examples set forth herein will come to mind to oneskilled in the art to which the present disclosure pertains having thebenefit of the teachings presented in the foregoing descriptions and theassociated drawings.

Therefore, it is to be understood that the present disclosure is not tobe limited to the specific examples presented and that modifications andother examples are intended to be included within the scope of theappended claims. Moreover, although the foregoing description and theassociated drawings describe examples of the present disclosure in thecontext of certain illustrative combinations of elements and/orfunctions, it should be appreciated that different combinations ofelements and/or functions may be provided by alternative implementationswithout departing from the scope of the appended claims.

What is claimed is:
 1. A method of cutting a reverse spot-face in aworkpiece, the workpiece comprising an obverse side, a reverse side, anda through hole with a central axis, the method comprising: installing apilot shaft in the through hole, wherein: a stop is along the pilotshaft on the obverse side of the workpiece, a biasing assembly is alongthe pilot shaft between the workpiece and the stop, and a thrust bearingis between the biasing assembly and the stop; attaching a reversespot-facing cutter to the pilot shaft on the reverse side of theworkpiece; biasing the reverse spot-facing cutter against the reverseside of the workpiece with a preload by generating a first thrust forceagainst the obverse side of the workpiece and a second thrust forceopposite the first thrust force against the stop by adjusting thebiasing assembly; and rotating the reverse spot-facing cutter via thepilot shaft.
 2. The method of claim 1, further comprising aligning thereverse spot-facing cutter with the central axis of the through holeusing the biasing assembly.
 3. The method of claim 1, furthercomprising: advancing the reverse spot-facing cutter into the workpiecewhile rotating the reverse spot-facing cutter; and progressivelyreducing the preload responsive to advancing the reverse spot-facingcutter.
 4. The method of claim 1, further comprising terminating thepreload when the first thrust force and the second thrust force fullydissipate.
 5. The method of claim 1, wherein rotating the reversespot-facing cutter via the pilot shaft comprises rotating the pilotshaft with a rotary drive.
 6. The method of claim 1, wherein the stop islocated between a first end and a second end of the pilot shaft, andwherein the biasing assembly comprises a workpiece-engaging member and astop-engaging member.
 7. The method of claim 6, wherein theworkpiece-engaging member and the stop-engaging member are adjustablyinterconnected.
 8. The method of claim 6, wherein the workpiece-engagingmember comprises: a third end that faces the workpiece; a fourth endopposite the third end and faces the stop; a second through holeextending between the third end and the fourth end, wherein the secondthrough hole has a first wall; and a first abutment surface that engagesthe workpiece.
 9. The method of claim 8, wherein the stop-engagingmember comprises: a fifth end that faces the workpiece; a sixth endopposite the fifth end and faces the stop; a third through holeextending between the fifth end and the sixth end, wherein the thirdthrough hole has a second wall; and a second abutment surface thatengages the thrust bearing.
 10. The method of claim 1, wherein, when thereverse spot-facing cutter is cutting the reverse spot-face: the pilotshaft is co-axial with the central axis, a cutting edge of the reversespot-facing cutter is substantially perpendicular to the central axis,the thrust bearing transmits the second thrust force from the biasingassembly to the stop, and the biasing assembly transmits the firstthrust force to the workpiece.
 11. A method of cutting a reversespot-face in a workpiece, the workpiece comprising an obverse side, areverse side, and a through hole with a central axis, the methodcomprising: installing a pilot shaft in the through hole, wherein: astop is along the pilot shaft on the obverse side of the workpiece, abiasing assembly is along the pilot shaft between the workpiece and thestop, wherein the biasing assembly comprises a workpiece-engaging memberand a stop-engaging member, wherein the workpiece-engaging membercomprises a first rotational engagement feature, and wherein thestop-engaging member comprises a second rotational engagement feature,and a thrust bearing is between the biasing assembly and the stop;attaching a reverse spot-facing cutter to the pilot shaft on the reverseside of the workpiece; biasing the reverse spot-facing cutter againstthe reverse side of the workpiece with a preload by generating a firstthrust force against the obverse side of the workpiece and a secondthrust force opposite the first thrust force against the stop byadjusting the biasing assembly; and rotating the reverse spot-facingcutter via the pilot shaft.
 12. The method of claim 11, furthercomprising aligning the reverse spot-facing cutter with the central axisof the through hole using the biasing assembly.
 13. The method of claim11, further comprising: advancing the reverse spot-facing cutter intothe workpiece while rotating the reverse spot-facing cutter; andprogressively reducing the preload responsive to advancing the reversespot-facing cutter.
 14. The method of claim 11, further comprisingterminating the preload when the first thrust force and the secondthrust force fully dissipate.
 15. The method of claim 11, whereinrotating the reverse spot-facing cutter via the pilot shaft comprisesrotating the pilot shaft with a rotary drive.
 16. The method of claim11, wherein the first rotational engagement feature comprises a firstinterlock feature having first opposed, substantially parallel wrenchsurfaces.
 17. The method of claim 16, wherein the second rotationalengagement feature comprises a second interlock feature having secondopposed, substantially parallel wrench surfaces.
 18. The method of claim11, wherein the workpiece-engaging member comprises a guide surface thatcenters the pilot shaft relative to the through hole in the workpiecewhen the reverse spot-facing cutter is installed on the workpiece. 19.The method of claim 11, wherein, when the reverse spot-facing cutter iscutting the reverse spot-face: the pilot shaft is co-axial with thecentral axis, a cutting edge of the reverse spot-facing cutter issubstantially perpendicular to the central axis, the thrust bearingtransmits the second thrust force from the biasing assembly to the stop,and the biasing assembly transmits the first thrust force to theworkpiece.
 20. A method of cutting a reverse spot-face in a workpiece,the workpiece comprising an obverse side, a reverse side, and a throughhole with a central axis, the method comprising: installing a pilotshaft in the through hole, wherein: a stop is along the pilot shaft onthe obverse side of the workpiece, a biasing assembly is along the pilotshaft between the workpiece and the stop, and a thrust bearing isbetween the biasing assembly and the stop; attaching a reversespot-facing cutter to the pilot shaft on the reverse side of theworkpiece; aligning the reverse spot-facing cutter with the central axisof the through hole using the biasing assembly; biasing the reversespot-facing cutter against the reverse side of the workpiece with apreload by generating a first thrust force against the obverse side ofthe workpiece and a second thrust force opposite the first thrust forceagainst the stop by adjusting the biasing assembly; rotating the reversespot-facing cutter via the pilot shaft by rotating the pilot shaft witha rotary drive; progressively reducing the preload responsive toadvancing the reverse spot-facing cutter into the workpiece whilerotating the reverse spot-facing cutter; and terminating the preloadwhen the first thrust force and the second thrust force fully dissipate.